Adjustable orifice gas-air mixer nozzle



Oct. 26, 1954 E. G. MURRAY 2,692,644

ADJUSTABLE ORIFICE GAS-AIR MIXER NOZZLE Filed July 16, 1951 INVENTOR.

Patented Oct. 26, 1 954 OFFICE ADJUSTABLE ORIFICE GAS-AIR MIXER NOZZLE Edward Gordon Murray, Denver, Colo.

Application July 16, 1951, Serial No. 236,992

3 Claims.

This invention relates to a gas orifice nozzle for gas burners, and has for its principal object the provision of an orifice nozzle which will produce a more efficient fuel mixture than the present types of fixed orifice nozzles.

Another object of the invention is to provide means for controlling the size and position of the orifice so that the flow of gas therethrough may be regulated to provide the most eificient gas and air mixture under all pressure conditions.

A further object is to incorporate an enlarged swirl chamber in a gas orifice nozzle which will create a palpitating vibration to the jet of gas for eificient entrapment and intermixture of the air therewith.

A still further object is to so construct the orifice member that it can be placed in position on jet bushings without requiring any change in the burner structure.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efficiency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

Fig. 1 is a fragmentary, longitudinal section through a conventional burner fuel mixer, illustrating the invention in place therein;

Fig. 2 is an enlarged, longitudinal section through the improved gas orifice nozzle; and

Fig. 3 is a still further enlarged front view thereof.

In Fig. 2 the orifice of the nozzle is illustrated in its fully open or aligned position, and in Fig. 3 the orifice is illustrated in the position of greatest mis-alignment.

In Fig. 1, parts of a conventional gas fuel mixing system are indicated by numeral as follows: gas main lil, mixing tube ll, air ports [2, orifice sleeve 13, and gas supply nipple l 4. The improved orifice nozzle is designed to fit into the orifice sleeve I3, and to be threaded onto the supply nipple M.

The improved gas orifice nozzle consists of a tubular barrel l5 having a closed front head 18 and an open rear end provided with internal threads 7 for receiving the threaded nipple M. The barrel is preferably provided with suitable wrench-engaging faces I6 to facilitate threading it onto the nipple M. The closed head [8 of the barrel I5 is reduced in diameter and externally threaded, as indicated at I 9, to receive an internally threaded, cup-like cap 20 corresponding in diameter to the barrel. The cap stops against a stop shoulder 2i on the barrel l5, and when threaded tightly against this shoulder, the cap wil be spaced from the head 18 to provide a thin, flat, circular swirl chamber 22 between the cap and the head.

The barrel head I8 is provided with an inner gas orifice 23, and the cap 20 is provided with a similar outer gas orifice 24. The two orifices are drilled simultaneously when the cap is tight against its shoulder 2| so that they will align with each other, as shown in Fig. 2. The aligned orifices 23 and 24 are positioned eccentrically of the common axis of the barrel and cap, the amount of eccentricity being slightly less than the diameter of the orifice. Thus, when the cap is rotated from the position of Fig. 2, to the position of Fig. 3, the outer orifices 24 will but slightly overlap the inner orifice 23.

When in place, the outer orifice 24 projects a jet of gas into the mixer tube II. The characteristics of this jet can be regulated and controlled by rotation of the cap 20 to various relative positions between the inner and outer orifices 23 and 24. In the majority of installations, the cap will be threaded tightly against its shoulder 2! so that the two orifices will align with each other at this point eccentric of the axis of the barrel Hi. This causes a high-frequency vibrating or pulsating, swirling action in the gas jet which efiiciently and effectively mixes and entraps air into the gas stream.

The exact reason for this unique action on the gas stream is not definitely known, but it has been found that if the cap 29 tightly engages the head [8, the action disappears. Therefore, it must be due to the action of the flat, circular, open swirl chamber 22, which apparently causes the gas to swirl intermittently into the outer jet opening 24, causing a vibrating interruption in the flow of gas at a high frequency. The action and characteristics of the jet and the mixture with the air can be regulated by rotation of the cap 20 to provide greater or less interference be tween the orifices, and to vary the capacity of the swirl chamber 22.

The air shutters usually provided on the air ports [2 may be entirely eliminated with the use of this improved jet nozzle, since perfect control of the gas and air mixture may be had by proper regulation and setting of the position of the cap 20.

While a specific form of the improvement has been described and illustrated herein, it is to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent 1. A gas jet, orifice nozzle comprising: a tubular barrel having an open rear end provided with internal threads; a closed front head formed. on said barrel; a cup-like cap rotatably mounted on said head; a closed bottom in said cap; means permanently spacing said bottom from said head to form a flat, circular, inner chamber in a plane at right angles to the axis of said barrel; a first gas orifice in said head; and a second similar orifice in said bottom, the axes of both of said orifices being eccentric of the axis of said head and cap, and the latter axis passing through both said orifices at all rotative positions of said cap.

2. A gas jet, orifice nozzle as described in claim 1 in which the closed front head is of lesser di ameter than said tubular barrel, and having an annular shoulder surrounding said head between said head and said barrel, said shoulder being positioned to be abutted by the sides of said cap and acting to prevent the bottom of said cap from contacting said head so as to maintain the orifice in said head fully open at all rotative positions of said cap.

3. A gas jet orifice nozzle as described in claim 2 in which the cap is threaded onto the head and in which the threads and the orifices in said head and in the bottom of said cap are relatively related so that when said cap is threaded inwardly toward said head to its maximum inward position, the bottom of said cap will be spaced from said head a minimum distance, and the orifice in said head will be in axial alignment with the orifice, in said bottom, and when said cap is threaded outwardly to increase the spacing between said head and the bottom of said cap, said orifices will move out of axial alignment with each other but will always remain in overlapping relation with each other.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,124,742 Hustus Jan. 12, 1915 FOREIGN PATENTS Number Country Date 597,643 Germany May 28, 1934 

